A high-sensitivity particle monitor using an integration sphere

Author

Watanabe, Kenzo ; Yamaguchi, Tomuo ; Nakayama, Masakatsu ; Gao, Yi-Zhu ; Nagasawa, Tadashi ; Ozawa, Taiyo

Author_Institution

Res. Inst. of Electron., Shizuoka Univ., Hamamatsu, Japan

Volume

49

Issue

3

fYear

2000

fDate

6/1/2000 12:00:00 AM

Firstpage

679

Lastpage

684

Abstract

A particle monitor is developed for real-time measurement of dust concentration measured in living and working environments. The principle of the device is based on the optical scattering method. An integration sphere is used to collect the light scattered by dust onto a photo-detector (PD). A double-modulated laser system, a low-noise current-to-voltage converter and a synchronous demodulator for averaging are used for the optical source and detector, respectively, to enhance the signal-to-noise ratio (SNR). Individual performances of the optical and signal processing units indicate that a dust concentration lower than 0.2 μg/m³ is detectable, but the minimum detectable concentration of an assembled prototype monitor is limited to 5 μg/m ³. This may be due to diffracted light and optical misalignment

Keywords

air pollution measurement; computerised monitoring; dust; light scattering; measurement by laser beam; optical information processing; signal processing equipment; SNR; averaging; current-to-voltage converter; diffracted light; double-modulated laser; dust concentration; high-sensitivity particle monitor; integration sphere; light scattering; living environment; optical misalignment; optical processing; optical scattering; photodetector; real-time measurement; signal-to-noise ratio; synchronous demodulator; working environment; Assembly; Demodulation; Light scattering; Monitoring; Optical detectors; Optical scattering; Optical signal processing; Particle measurements; Particle scattering; Signal to noise ratio;

fLanguage

English

Journal_Title

Instrumentation and Measurement, IEEE Transactions on

Publisher

ieee

ISSN

0018-9456

Type

jour

DOI

10.1109/19.850414

Filename

850414